Information
This policy setting specifies whether Virtualization Based Security is enabled. Virtualization Based Security uses the Windows Hypervisor to provide support for security services.
The recommended state for this setting is: Enabled.
Note: Virtualization Based Security requires a 64-bit version of Windows with Secure Boot enabled, which in turn requires that Windows was installed with a UEFI BIOS configuration, not a Legacy BIOS configuration. In addition, if running Windows on a virtual machine, the hardware-assisted CPU virtualization feature (Intel VT-x or AMD-V) must be exposed by the host to the guest VM.
More information on system requirements for this feature can be found at Windows Defender Credential Guard Requirements (Windows 10) | Microsoft Docs
Note #2: Credential Guard and Device Guard are not currently supported when using Azure IaaS VMs.
Rationale:
Kerberos, NTLM, and Credential manager isolate secrets by using virtualization-based security. Previous versions of Windows stored secrets in the Local Security Authority (LSA). Prior to Windows 10, the LSA stored secrets used by the operating system in its process memory. With Windows Defender Credential Guard enabled, the LSA process in the operating system talks to a new component called the isolated LSA process that stores and protects those secrets. Data stored by the isolated LSA process is protected using virtualization-based security and is not accessible to the rest of the operating system.
Impact:
Warning: All drivers on the system must be compatible with this feature or the system may crash. Ensure that this policy setting is only deployed to computers which are known to be compatible.
Solution
To establish the recommended configuration via GP, set the following UI path to Enabled:
Computer Configuration\Policies\Administrative Templates\System\Device Guard\Turn On Virtualization Based Security
Note: This Group Policy path may not exist by default. It is provided by the Group Policy template DeviceGuard.admx/adml that is included with the Microsoft Windows 10 RTM (Release 1507) Administrative Templates (or newer).
Default Value:
Disabled.